Valve mechanism for engines.



No. 856,594. PATENTED .TUNE 11, 1907. L. D. LOVEKIN. VALVE MECHANISM POR ENGINES.

APPLIoATIoN FILED JULY a, 190e.

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M5505 6% New? No. 856.594. PATENTED JUNE 11, 1907. L. D. LOVEKIN. VALVE MEGHANISM POR ENGINES.

10N FILED JULY, 19ndl APPLIOAT 3 SHEETS-SHEET 2.

VALVE MEGHANISM FOR ENGINES.

APPLIOATION FILED JULYe, 190e.

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UNITED STATES PATENT ernten.

MARSHALL T. DAVIDSON,

OF BROOKLYN, NEW YORK.

VALVE lVlECHANlSIVl FOR ENGINES.

Application filed July 6,

T0 all whom t 1mi/y concern:

Be it known that I, LUTHER D. Lovnxix, a citizen of the United States, and a resident of Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented a new and useful Improvement in Valve Mechanism for Engines, of which the following is a specification;

My invention relates to valve mechanism Vfor engines and more particularly to valve mechanism 'for use in connection with the piston valve of a pumping engine where the live steam is admitted through the valve and the exhaust comes in contact with the valve.

The object is to remove the lateral pressure from the valve and to balance it both as to endwise and lateral pressure.

A practical embodiment of my invention is represented in the accompanying drawings, in which Figure 1. is a vertical section through the cylinder and valve mechanism ot' a pumping engine, the section being taken in the plane of the longitudinal axis of the piston valve,

Fig. 2 is a similar view taken in the plane of the line AA ol" Fig. 1, at right angles to the section shown in Fig. 1, Figi 3 is a top plan view, and Fig. 4 is a view in detail oli the cam for operating the piston valve.

The engine cylinder is denoted by 1: its piston by 2 and the casing for the piston valve for controlling the admission of steam to and its exhaust from the cylinder 1, is denoted by 3. These may be ot well known or approved form.

The live steam is admitted through a pipe 'i in communication with a chamber 5 shown in dotted lines, Fig. 1, and is conducted thence through suitable ports 6 and 7, also shown in dot-ted lines, to a passageway S (see Fig. 2) which leads to the interior of the valve casing 3.

The piston valve comprises two hollow heads, the one denoted b y 9 and the other by 10, these heads being connected by a horizontal web 11 and two upright webs 12 and 13 (see Fig. 2), the latter being spaced apart to form a chamber 1-1 between them, the said chamber being bounded by the said two webs 12 and 13, the inner walls of the piston heads 9 and 10, the horizontal web 11 and the top of the casing The interiors of the piston heads 9 are in communication with each and 10 other Specification of Letters Patent.

Patented June 11, 1907.

1906. Serial No. 324,995.

through passageways 15 and 16 on the outer sides of the webs 12 and 13, respectively, the one 16 being in position to communicate with the steam inlet passage 8 thus permitting live steam to circulate Vfreely within piston heads. This steam, however, is prevented lrom exerting an undue downward pressure on the piston valve because of the upright webs 12 and 13 which keep it conlined intermediate ot the two piston heads to comparatively narrow spaces on opposite sides ol' the valve and the bottoms of these spaces are only slightly greater lin extent than the upper walls or tops oll these passages, iust enough greater to give the valve the desired natural seating pressure.

The chamber 14. hereinabove described is open to the exhaust through openings 17, 1S, in the horizontal web 11.

Steam is admitted from the interiors of the hollow piston heads to the opposite ends of the cylinder 1 by means of passageways 19, 20, which register alternately with ports 21, 2.2, in the hollow piston heads 9 and 10. As shown, the passageway 19 leads to the lower end ot the cylinder 1 and the passageway 2O to the upper end` These passageways 19 and 20 also act alternately as .steam inlet and exhaust ports, as is usual. They are brought alternately into communication' with the main exhaust chamber 23 by the longitudinal movement ot the piston valve formed by means of a cove 24 beneath the horizontal web .11. This exhaust chamber 23 communicates with an exhaust passageway .25 leading to an exhaust chamber 26,

shown in dotted lines, Fig. 1, and thence to the exhaust pipe 27.

l The piston valve is moved longitudinally to open and close the steam inlet and exhaust ports leading to the opposite ends of the cylinder 1 by means of a depending pin 2S engaged with a rocking cam 29 connected with a stha'lt 30 and operates by mechanism of well known or approved form, not shown. The slot 31 in the cam Z9 is not only so vformed as to impart a longitudinal movement to the piston valve at its opposite ends engaged with the pin 2S but it is set oblique so that it imparts to the piston valve a limited rocking movement on its axis at the same time that it is moved longitudinally. This rocking movement of the valve serves to exhaust the steam which might otherwise be compressed bethe two A lOO IOS

tween the opposite ends of the piston valve and the ends of the valve casing, as follows To balance the piston valve and prevent it from working against vacuum, small openings 32, 33, are made in its ends to permit the live steam to pass from the interior of the piston heads into the valve casing between the heads and the ends of the casing. l/Vhen the valve is forced to the limit of its movement in one direction or the other, there is a tendency to compress the steam so utilized for balancing purposes and this is permitted to be exhausted by ports 34 and 35 in the wall of 'the valve casing and in communication,

respectively, with passageways 36 and 37 leading to the exhaust chamber 23. For instance, as the valve approaches the position shown in Fig. Vl and tends to compress the steam between its head and the end of the valve casing, the cam 29 will so rock the I valve as to open the port 34 to the passagel way 36 and when approaching the opposite l limit it will be rocked in a direction to open the port 35 to the passageway 37 and permit the exhaust.

By opening the horizontal web or diaphragm 1l to permit the exhaust steam to pass intothe chamber above it, the valve is balanced so far as the pressure of the exhaust steam is concerned while the pressure of the live steam thereon is substantially balanced as hereinabove particularly described.

The valve construction as described, may be formed in a single casing and the wear and l energy required to operate it are both materially reduced.

What claim isz- 1. A valve comprising hollow piston heads separated by a web or diaphragm, the interiors of the said piston heads being in communication with one another by passageways located on opposite sides of the valve and spaced apart by an exhaust chamber.

2. A valve comprising hollow piston heads connected by a perforated diaphragm, a valve casing within which the valve is seated, an exhaust chamber below the said perforated diaphragm, an exhaust chamber between the hollow piston heads of the valve and above the said perforated diaphragm vand means for admitting live steam to the hollow piston heads at one side of the exhaust chamber in the piston valve.

3. A valve comprising hollow piston heads connected by webs or diaphragms spaced apart and connected by a perforated cross web or diaphragm, a valve casing, means for reciprocating the valve longitudinally within the casing and means for rocking the valve during its reciprocating movement, the said diaphragms forming exhaust chambers between the hollow piston heads of the valves above and below the said perforated diaphragm.

In testimony, that l claim the foregoing as my invention, I have signed my name in presence of two witnesses, this twenty second day of June, 1906. l

. LUTHER D. LOVEKIN. lVit-nesses R. A. WTORKMAN, C. B. GRoFF. 

